Method and device for obtaining an IP address

A processing method, implemented by a domain name server (DNS server) associated with a network supplying an Internet protocol (IP) connectivity service to at least one client device, said method comprising:

• receiving, from said client device, a first request requesting for a first network resource a record of AAAA type to obtain an IPV6 address in order to access the network resource, the first network resource being associated to a domain name and having IPv4 connectivity, and in which there is inserted the domain name associated with the first network resource and an additional piece of information specifying a type of IP address of the first network resource expected by said client device from said DNS server in response to said first request if said first network resource has IPv4 connectivity, said expected type of IP address being able to be an IPv4 address of the first network resource or a fake IPV6 address of the first network resource, and wherein the client device has only IPv6 connectivity;
• obtaining an IPV4 address of said first network resource;
• and
• sending a response to said first request containing at least one IP address determined by the DNS server from said IPv4 address obtained and corresponding to the type of IP address expected by the client device,
• wherein the DNS server is a server distinct from a “nominal” DNS server with which the client device has been configured by an operator of the network, and
• wherein said piece of information inserted into the first request has a predefined value known to the DNS server, and said at least one IP address determined by the DNS server is the IPV4 address of the first network resource obtained.

A client device connected to at least one network supplying an IP connectivity service to the client device, said client device comprising:

• a processor;
• and
• a non-transitory computer readable medium storing computer-executable instructions which when executed by the processor configure the client device to:
• determining whether said network implements a function for converting IPv4 packets into IPv6 packets;
• insert, into a first request requesting for a first network resource a record of AAAA type to obtain an IPV6 address in order to access the first network resource, the first network resource being associated to a domain name and having IPv4 connectivity via said network, intended for a domain name server (DNS server), the domain name associated with the first network resource and an additional a piece of information specifying a type of Internet Protocol (IP) address of the first network resource expected by said client device from said DNS server in response to said first request, said expected type of IP address being able to be an IPV4 address of the first network resource or a fake IPV6 address of the first network resource, and wherein said client device has only IPV6 connectivity;
• and
• send said first request to the DNS server,
• wherein:
• the DNS server is a server distinct from a “nominal” DNS server with which the client device has been configured by an operator of the network;
• the determining comprises sending, to the nominal DNS server, a second request to obtain an IPV6 address in order to access a given second network resource known to have only IPv4 connectivity;
• and
• if a positive response is received from the nominal DNS server comprising an IPV6 address for said given second network resource, the client device determines that the network implements the function for converting IPv4 packets into IPv6 packets.

A domain name server (DNS server) comprising:

• a processor;
• and
• a non-transitory computer readable medium storing computer-executable instructions which when executed by the processor configure the DNS server to:
• receive, from a client device connected to a network supplying an Internet Protocol (IP) connectivity service to said client device, a first request requesting for a first network resource a record of AAAA type to obtain an IPV6 address in order to access via said network the first network resource, the first network resource being associated to a domain name, and said client device having only IPV6 connectivity;
• detect, in said first request, the domain name associated with the first network resource and an additional a piece of information specifying a type of IP address of the first network resource expected by said client device from said DNS server in response to said obtaining request if said first network resource has IPv4 connectivity, said expected type of IP address being able to be an IPV4 address of the first network resource or a fake IPV6 address of the first network resource;
• if said first network resource has IPv6 connectivity, send, to the client device, in response to said first request, an IPV6 address of said first network resource;
• and
• if said first network resource has IPv4 connectivity:
• obtain an IPv4 address of the first network resource;
• and
• send a response to said first request containing at least one IP address in order to access said first network resource determined by the DNS server from said IPv4 address obtained and corresponding to the type of IP address expected by the client device indicated by said piece of information inserted into said first request,
• wherein the DNS server is a server distinct from a “nominal” DNS server with which the client device has been configured by an operator of the network, and
• wherein said piece of information inserted into the first request has a predefined value known to the DNS server, and said at least one IP address determined by the DNS server is the IPV4 address of the first network resource obtained.